Power take-off unit for tractors



May 13, 1930. J. CAMPBELL POWER TAKE-OFF UNIT FOR TRACTORS I fizz/372%)?HI T III J J I g I li ori inal Filed 001;.4, 1926 .2 Sheets-Sheet 1 mmmm m May 13, 1930. J. CAMPBELL POWER TAKE-OFF UNIT FOR TRACTORS OriginalFiled Oct. 4. 1926 2 Sheets-Sheet' 2 QM WN w Q s k Patented May 13, 1936UNITED STATES LEON JAY CAMPBELL, O

F BUCHANAN, MICHIGAN rowan TAKE-err UNIT FOR TRACTORS Originalapplication filed October 4, 1926, Serial No. 139,250. Divided and thisapplication filed March 17,1927. Serial No. 176,086.

This invention relates to power take-ofi's for tractors, and moreparticularly for Fordson tractors, so that the tractor may be providedwith a belt pulley or other power delivery member by means of whichstationary or other machinery may be operated bythe tractor engine.

In power take-offs as heretofore made and used, the clutch of the unitcan not be released 1 while the unit is under load without firstdisengaged without a corresponding operation of the tractor clutch, thusmaking the device inconvenient to operate with many operations and manyoperators. Then again,-in these units as heretofore placed on themarket, the driving and driven shafts have not been supported in amannerto keep their meeting or adjacent ends in proper alignment on'theapplication of power or undue.

strains thereon. This places unnecessary wear and strains on thebearings and gears and causes the shafts to weave,

ing the belt operating on the belt pulley a wabbling or whipping action,with resultant loss of power and unduewear an the bearings of both theunit and the machinery driven thereby. I

The object of my invention is to provide a power take-off unit whichovercomes theobjections heretofore noted and also to provide a type ofclutch for the unit which may be operated independently of the clutch ofthe tractor whenever desired, thereby allowing the unit to be readilyreleased from the power element of the tractor without beingrequired todisengage the tractor clutch. This allows the unit to be disengaged fromthe tractor 1 the instant desired, thereby making thedethereby giv-vOctober 4, 1926, has referenceto the means which I have devised forrocking the clutch key to move its lug into and out of clutched vengagement with the associated sleeve'or rotary member. 7

In the accompanying drawings Fig. 1 is a longitudinal vertical sectionalview taken through a power take-off unit constructed in accordance withmy invention;

Fig. 2 is an elevational view of the driving and driven shaft assemblywith parts in section;

Fig. 3 is a longitudinal vertical sectional view through said shaftassembly on line, -33 of Fig. 1; and

Figs. 4, 5, and 6 are transverse vertical'sectional views taken on lines44, 5-5, and 6-6, respectively, of F ig. .1.

In thedrawings, lrindicates the tractor housing having an'openingthrough which the inner end of the casing 2 of my improved unit isinserted, as shown in Fig. 1. This casing hasa surrounding flange 3, sothat it may be secured to the tractor housing, with the casing 2extending outward therefrom, as shown. Said casing 2 is preferably inthe form of a onepiece casting and has a length to-eXt-end from end toend of the unit.

Atthe inner end of the casing 2, that is, the end within the tractorhousing 1, there is a beveled gear at, which meshes with a beveledgear(not shown) of the tractor transmission. Thehubof the'gear 4 is made inthe form of a stub shaft'6, which extends into the adjacent .end'of thecasing 2. An antifriction bearing 7 is mounted in theinner end of thecasing 2 to support the shaft 6, as shown. The inner end of the shaftr6extendsinto a sleeve 8 journaled in the casing 2, the shaft 6 beingfixed to the sleeveby a key 9 and apin 10, the latter holding the partsagainst endwise displacement. (See Figs. 1 and 5.)

The casing 2 is provided with a bore to receive and support the sleeve8. This bore extends along the length of the sleeve and provides arelatively wide bearing surface therefor. This surface in total is wideenough to properly support the sleeve and maintain it in correct axialalignment with the gear 4 and the driven shaft, to be presentlydescribed, and also to provide sufficient metal in the bearing to carryoff all heat likely to be produced during the rotation of the sleeve. Bymaking this bearing wide enough, there is no improper wearing of theteeth of the bevel gears, thus prolonging the life of the unit andmaking a quiet running mechanism.

The bearing surfaces mentioned are marked 11, 12 in the drawings, andthese are separated by an annular oil groove 13 made in the bore andsurrounding the sleeve. This groove communicates with an oil well 14formed as a longitudinal groove in the lower portion of the bore alongthe under 7 side of the sleeve 8, as shown in Fig. 1. The

casing 2 has an inlet opening 15 on its upper side for feeding lubricantfrom the tractor housing to the groove and well 13, 14, respectively.The sleeve 8 has oil holes 16 in register with the groove 13, so thatoil may flow into the interior of the sleeve; The, casing 2 has-an oiloutlet passage 17 in its under side so as to return oil from theinterior of the casing 2 to the supply in the tractor housing 1.

A belt pulley 18 or other power delivery member is located at the outerend of the casing 2. This pulleyis fixed to the outer end of a drivenshaft 19 in any suitable manner so as to be rotated thereby. The shaft19 extends into the casing 2 through an antifriction bearing 20 mountedin the outer end of thecasing, as shown. The shaft 19 extends intothesleeve 8 and terminates just short of the portion of the shaft 6within the sleeve, as shown in Fig. 1. At such point the shaft 19 isreduced, as a 21, and is supported in the sleeve 8 by a relatively widebronze bushing 22, which is fitted in the sleeve, as shown.

The shaft 19 is provided with a concave groove or key seat 23 extendinglengthwise thereof and in that portion extending inside and outside ofthe sleeve 8, respectively. Rockably mounted in this groove is a key 24extending substantially the full length of the groove or key seat, asshown in Figs. 1, 2, and 3. The key 24 thus has a portion within andoutside the sleeve, respectively. The end of the sleeve 8 where theshaft 19 extends into it is provided witha plurality of inter-- nalprojections 25, as clearly shown in 4. The key 24 is provided with alocking lug 26 adapted in the rocking of the key to be lines in Fig. 2.

to properly'rock the key, be positively eifecte'd on shifting the collar7 turned into and out of clutched engagement with the projections 25.(See Fig. 4.)

When the key is rocked axially in one direction, the lug 26 isdisengaged from the projections 25 so as to disconnect the sleeve 8 fromthe shaft 19 and thus permit the gear 4 to be rotated by the tractorengine without imparting power to the pulley 18. When the key is rockedin the opposite direction, the lug 26 is extended up into the spacebetween two of the proj ections25 and looks or clutches the sleeve 8 tothe shaft 19 so that power may be transmitted from the tractor engine tothe pulley 18. The key 24 is held against endwise movement by a pin 27and a collar 28 at the opposite ends of the key. The pin 27 is driveninto the shaft 19 at the front of the key, while the collar 28 has atight fiton the shaft at the rear end of the key, as shown in Figs. 1,2, and 3. The pin 27 is located in the key groove 23 so as to be withinthe bushing 22, asclearly shown in Fig. 3. i

The mechanism so far described constitutes the subject-matter of my saidcopending application.

To rock the key, a shift collar 29 is slidably mounted on the portion ofthe shaft 19 out side of the sleeve 8. The key 24 has a .pair of camprojections 30, 31 arranged on opposite sides of its longitudinal axisand on opposite sides of the collar 29 so that the collar on being slidendwise on the shaft will rock the keyby riding over these projections.

WVhen the collar 29 slides over the projection 30, the key is rocked todisconnect the sleeve 8 from the shaft 19 (see Fig. 3) whereas,

when the collar is slid over the other projection .31, the key is rockedto connect the sleeve 8 with the shaft 19. (See Fig. 1.)

A spring 32 iscoiled about the rear end of the key 24 and has one endconnected with the key and the other endbearing against the shaft 19.- aThis spring constantly tends to rock the key in a direction to turn itslug 26 into locking or clutching. position. The collar 29 has a widthless than the distance between the projections 30, 31, so that saidcollar may be free of both projections when in a position between them,as shown in dotted Thus the spring 32 may act to rock the key intoclutched engagement with the sleeve 8 after the collar frees theprojection 30, but before it acts'on the projection 31. Should thespring break or fail 29 over the projection 31. 'The outer contour ofthe key adjacent each cam pro ection conforms to the curvature of thebore of the collar so that the key is held from rocking while the collaris over either projection, as shown in Fig. 6.

To slide the shift collar 29on the shaft 19,

the operation will I provide a shift lever (not shown) extending up outof the top of the casing 2 and within convenient reach of the operator.This lever is pivoted in the casing between its ends and carries a shoeat its lower end with the shoe fitting in the annular groove in theouter periphery of the collar so that the latter may be slid back andforth by the lever. The shift collar 29 is keyed to the shaft 19 so asto rotate therewith andthus prevent burning the cam faces of theprojections 30, 31. This connection comprises a pin 38 carried by thecollar 29 and extending into an elongated slot 39 in the shaft 19, asshown in Fig. 3. A spring pressed check device (not shown) is carried bythe casing 2 at one side of the shift lever and cooperates,

therewith in a manner to hold the lever in either of its shiftedpositions. I employ a latch member (not shown) which isengageable withthe operating lever of the tractor clutch to hold the shift lever frombeing accidentally moved into clutch engaging position.

The sleeve 8 in being keyed or fixed to the stub shaft 6 of the gear 4,constitutes in effect the driving shaft of the unit. By provid-' ing arelatively wide bearing (11-12) for this shaft in the casing 2 andhaving the driven shaft 19 supported in the sleeve by a relatively widebushing 22, the driving and driven shafts are supported in correct axialalignment at all times so that there is no opportunity afiorded forthese shafts to run eccentric and cause undue wear on the bearings orthe teeth of the bevel gears, or throw" described, the driving anddriven shafts 8' and 19 of the unit may be readily andeasilydisconnected without the necessity of first disengaging the clutch .ofthe tractor, as

heretofore, for the reason that the clutch key- 24 is rolled down out ofengagement with the sleeve 8 regardless of the load strains on theshafts or their speed of rotation. Thus, the

clutch key 24 maybe operated whenever de-v sired, independently of thetractor clutch,- with the result that the machine or other device drivenby the tractor may be quickly and easily disconnected therefrom withoutthe delay incident to mounting the tractor quickly disconnected from thetractor by simply releasing the clutch of the unit.

The details of construction shown and described may be variously changedand modified without departing from the spirit and scope of myinvention.

. I claim as my invention: I l

1. In a power transmitting device, the combination with a shaft, of arotary member surrounding the shaft, a clutch key rockably mounted onthe shaft and heldagainst endwise movement thereon, said key having acam projection, a shift collar slidably mounted on the shaft over thekey and moving the same out of clutched engagement with said rotarymember upon sliding the collar over said projection, and spring meansabout one end of the key and acting thereon to move the key intoclutched engagement with the rotary member on sliding the collar off ofsaid cam projection.

2. In a power transmitting device, the combination with a shaft, of arotary member surrounding the same, a clutch key rockably mounted on theshaft and held against endwise movement thereon,'said key having opposedcam projections on opposite sides of its longitudinal axis, a shiftcollar slidably mounted on. the shaft over the key and cooperating withsaid projections to effect the movement of the key into and out ofclutched engagement with said rotary member, and spring means acting onthe key to move the same into clutched engagement with the r0 tarymember when the collar is free of both cam projections, said collarhaving a width less than the distance between said projec tions.

3. In a power transmittingassembly, the combination with a shaft,'of arotary member bored to receive the shaft and surround the same, a clutchkey rockably mounted on the shaft for releasably connecting the rotarymember thereto, opposed'cam projections on the key, a shift collarslidably mounted on the and adapted to effect the movement ofthe keyinto and out of clutched engagement with the rotary member in thesliding of thecollar over said projections, said collar having anannular projection to enter and fit within the bore ofthe rotary memberto support the same when the key clutches the rotary member to theshaft. V

In testimony whereof I afiix my signature this 4th day of March, 1927.

, LEON JAY CAMPBELL.

and throwing out the tractor clutch, as here'- tofore. This is animportant feature of my invention, because it provides a safety factorin case of accident either to the machine driven by the tractor or tothe operator attending the same, as the machine may be.

11. shaft over the key between said projections

